It is possible to look up the documentation for any built-in or library predicate from within Emacs (using C-c ? or the menu). For this to work, Emacs must be told about the location of the ‘info’-files that make up the documentation.
If you load the file sicstus_emacs_init.el from your .emacs file, Emacs should be able to find the SICStus documentation automatically; see Installation: